1. Technical Field
The present invention relates to a driving assist controller for a vehicle, such that various on-board control devices of the vehicle are adequately actuated according to the environment ahead of the vehicle.
2. Related Art
Various driving assist controllers for a vehicle have recently been developed and put to practical use. With such devices the shape of the road ahead of the vehicle and three-dimensional objects, such as vehicles and obstacles, present ahead of the vehicle are detected using a camera or radar to ensure safe traveling on the road and prevent collisions with the objects. For example, Japanese Unexamined Patent Application Publication (JP-A) No. 2003-16597 discloses an obstacle information presenting device which is a warning device that detects the shape information on a road, detects obstacle information on an obstacle present on the road by road-vehicle communication, calculates a visibility distance that can be viewed by a driver on the basis of the shape information on the road, and where an obstacle is detected on the road, issues a warning at a timing corresponding to a deceleration distance required to stop the vehicle before the obstacle at a predetermined deceleration. In such a warning device, when the visibility distance is equal to or less than a deceleration distance, a warning generation timing is set earlier than a timing corresponding to the deceleration distance.
With the warning device such as disclosed in JP-A No. 2003-16597, since the warning issuance timing is changed by taking into account the driver's visibility, the warning is performed in a manner closer to driver's senses than in the conventional warning devices that issue a warning in a simple manner at a fixed deceleration distance. However, since the driver's visibility changes from moment to moment under the effect of, for example, mist or blizzard, when the warning generation timing is changed without taking such changes into account, the warning generation timing is affected by changes in visibility and becomes unstable, and erroneous operations or unnecessary ON/OFF operations may be repeated. Further, in recent years various control devices such as an antilock brake system (ABS), skid preventing control device, and brake assist control device have been installed on the vehicles with the object of improving stability and safety thereof. In such control devices, implementing the control with consideration for driver's visibility also ensures more natural and accurate control, and when the onboard control devices are actuated without consideration for changes in visibility, the operation thereof is also affected by changes in visibility and becomes unstable, and it is possible that erroneous operations or unnecessary ON/OFF operations are be repeated. Meanwhile, in a case where sudden mist or blizzard occurs, the visibility is degraded, and when the driver fails to recognize, determine, and respond to the degradation of visibility, the most dangerous consequence of such poor visibility ensues. Hence, warning and control that take into account the degradation and restoration of visibility are required.